Separating minerals by flotation.



ANSO N G. BE'ITS, F STOCKHOUSE, NORTH. CAROLINA.

SEPARATIN-G MINERALS BY. FLO'IATIOII.

Specification of Letters Patent.

Patented Dec. 10, 1918.

No Drawing. Application filed August 14, 1914, Serial No. 856,755.Renewed June 1, 1918. Serial No. 237,835.

tree, the special object being to increase the percentage of recovery ofthe metal sulfids from the same, and incidentally to extract a portionof the valuable metal insolution.

In the particular processes to which my invention has reference, theseparation of the metals from the gangue is effected partially or whollyby the. flotation of the metallic particles on a body of water While theearthy particles or gangue are permitted to sink.- This process may becarried out in manyways, but usually some preliminary treatment of thecommin-uted ore is resorted to in order to make the metal particles morebuoyant. This in most of the prior processes has been done by the use ofoil which is mixed with the material for the purpose of coating themetal particles and by the employment of some process which willdisseminate through the Water in which the ore is-contained fine bubblesof air or gas which attach themselves to the metal and cause the same tofloat.

I have discovered that in case of such ores as contain metallic sulfids,for example, cuprous sulfid or chalcocite, if the particles of sulfid becoated with an imperceptibly thin film of sulfur, they will have a muchstronger afiinity for the air bubbles, and for the oil also, in theevent that the latter is used. A coating of spongy, sticky sulfur may bereadily produced on the sur face of particles of metallic sulfidminerals by adding to a body of water in which. such materials arecontained in a finely divided state any chemicals that will give thebath an oxidizing reaction, and then agitating the water and ore, W1th aflotation agent, such as oil. This decomposes the metallic sulfid ontheir surface, extracting traces of metal, and leavin a, film or sulfur,which has a strong ailinity for bubbles of air or gas and the oil,resulting in an increased buoyancy of the particles, which float to thesurface and may be skimmed off. By this or similar processes a, muchlarger extraction of metal by flotation may be secured.

Many chemicals may be used for this purpose, such as ferric sulfate,'ferric chlorid. bleaching powder, chlorin or an acid having an oxidizingaction. For copper ores, I prefer to use chlorin, as it will dissolvecopper oxide in the presence of limestone, and will also dissolve thefinest and mostdiflicultly extractable cuprous sulfid, which may berecovered from the liquid of the bath, for example by precipitating thecopper from the liquid, in the form of a sulfid, so that a practicallyperfect extraction of the metal may be secured.

In the process described, the chemical reactions taking place areprobably as follows:

In the event that the ores contain reducing added to overcome thereducing action of such compound.

In the claims I mean to include under the term flotation agent any one,or more of the materials air, gases or oils.

What I claim is:

1. The process of treating ores containing metal sulfids, whichcomprises agitating the ore containing metal sulfid in a finely dividedcondition with an aqueous vehicle and a flotation agent, producing anoxidizing reaction in the bath by adding an oxidizing reagent theretocapable of producing films of free sulfur on the particles of metalsulfid, subjecting the treated ore to the action of a gas in finelydivided form in the presence of said flotation agent and a liquidvehicle, in order to form a scum containing the major portion of thevaluable metal sulfid.

2. A process of treating finely divided ores containing metal sulfidwhich comprises treating the same in 'abath containing a flotationagent, adding an oxidizing agent capable of producing a film containingfree sulfur upon the ore particles, and thereafter floating the oreparticles.

3. A process of treating ores which comprises agitating a finely dividedore containing a metal sulfid, with a flot ti agent 3 and watercontaining in solution an oxidizmg substance capable of reactingchemically with the sulfid, and producing films of sulthe presence ofsaid flotation agent, and a' liquid vehicle, and removing the scum fromthe bath.

4. A method of treating ores which comprises agitating sulfid ore in afinely divided state with Water containing chlorln gas in solution, anda flotation agent, separating the scum containing the ore particles fromsaid Water.

5. The herein described method of increasing the buoyancy of metalsulfids in finely divided ores, which comprises produo- 15 ing upon theparticles of such sulfids by oxidation of a portion thereof, a thin filmcontaining free sulfur to increase the aflinity of the sulfid forbubbles.

In testimony whereof I afiix my signature 20 in the presence of twosubscribing witnesses.

ANSON G. BETTS.

Witnesses:

THOMAS 'J. BYRNE, WILLIAM F. JOHNSON.

